Abstract: Intelligent bionic leg (IBL) controlled by magneto-rheological (MR) damper is an advanced prosthesis. This paper introduced the conception, research purpose and configuration of IBL. Kinematics model and dynamics model were deduced in detail and modified sigmoid model of MR damper was proposed. Then control model of IBL was discussed and combined control simulation was performed. The result indicates that IBL controlled by MR damper can track human normal gait well.